Robots have been all over the news lately, from DARPA's announcement of the semifinalists for its upcoming test of self-driving cars in an urban environment, to today's AP report that the Pentagon intends to order 3,000 more IED-hunting bots over the next five years. All the recent buzz surrounding 'bots might be one of the early signs of the same rising trend that buoyed other familiar technologies.

In a recent blog posting, Wired's Noah Shachtman noted that U.S. military robots "ran 30,000 missions in 2006." He added that 1,000 robots will be employed in military settings by the end of the year, with another 2,000 expected within the next five years. That growth may not sound significant, but I'd argue that dismissing this upward trend could be a colossal mistake. Just consider the growth of planes, trains, and automobiles.

All aboard!
According to John Steele Gordon, in his book An Empire of Wealth: The Epic History of American Economic Power, there were only 23 miles of railroad track in the country in 1830. By 1840, that figure had increased to 2,818 miles; by 1850 there were 9,021; and by the Civil War, the number of miles had spiked to 30,626.

My point is that it would have been easy to dismiss the significance of the railroad in 1830, when it had only 23 miles of track. Today, is it not similarly possible to dismiss the significance of the emerging robotics industry, when there are only 1,000 military robots in the field?

In one sense, the jump from 1,000 robots to 3,000 robots in five years may appear slow -- almost linear in nature. But I'd argue that the trajectory for robotics is more likely exponential, and that in 10 years, there could be 10,000, or maybe even 20,000 robots patrolling the battlefield. My optimism stems from the Army's recent decision to begin deploying gun-toting robots in combat, and the Defense Departments ambitious plans to have robots compose one-third of the U.S. fighting force by 2015.

The opportunity for investors is to determine which companies might be supplying these robots. Today, Foster-Miller, iRobot (NASDAQ:IRBT), Boston Dynamics, and even such powerhouses as Microsoft (NASDAQ:MSFT) rank among the field's more notable companies.

The lesson of cars
Like John Candy's modes of travel in the hit movie Planes, Trains, and Automobiles, locomotion is just part of the story. In 1900, a mere 4,000 automobiles were manufactured in America, by scores of different companies. Just three years later, fifty-seven new automobile companies came into existence -- and twenty-seven went bankrupt that same year.

Therein lies the second historical lesson. Today, there's no shortage of promising robotics companies -- Exponent, Boston Dynamics, Evolution Robotics, and Hanson Robotics, to name but a few. Some will undoubtedly become formidable forces in the robotics industry, while others carve out successful niches. But many others will go the way of those early automobile pioneers.

Unfortunately, not all companies are created equal. Management, money, and technological prowess will help separate the winners from the losers, and the robotics industry can expect a shakeout similar to that of the early automotive industry.

Automobile history is also teaches us to expect falling prices as companies develop expertise and achieve economies of scale. Henry Ford of Ford Motor Company (NYSE:F) introduced the Model T in 1908, and sold 10,607 of the cars that year at $850 each. By 1916, the father of the assembly line had decreased the price to $360, and increased the annual number sold to 730,041.

Before blindly assuming that robotics is the next big thing, investors should look closely at what larger companies such as Toyota (NYSE:TM), Honda (NYSE:HMC), and John Deere (NYSE:DE) are already doing in this field. As great as many of the smaller companies' robotic advances will likely be, if they can't compete on price, they might become nothing more than a historical footnote.

The sky's the limit
 Scientific American recently noted that in 1905 -- just two years after the Wright Brothers took their inaugural 12-second, 120-foot flight -- a single plane flew a distance of 24 miles, farther than all of the flights made in 1904 combined! That's an extraordinary amount of progress in such a short period of time. Of course, that was just the beginning of the story. By 1927, Charles Lindbergh had flown across the Atlantic; in 1969, man reached the moon.

The pace of progress for the robotics industry is impossible to predict, but if one follows the advances being made in the fields of material science, computers, sensors, and software, it's easy to imagine that robots will also become significantly more capable.

Today, robots vacuum and scrub our floors; tomorrow, they might be reliable household companions helping millions of senior citizens to live independently in their homes. These bots could not only keep the place tidy, but also by fetch things, serve meals, and even unobtrusively monitor their owner's health.

Rise of the machines?
Planes, trains, and cars each grew exponentially cheaper, more effective, and more numerous over relatively short periods of time. Their success provides ample indications that robotics could follow suit. Investors with the foresight, patience, and willingness to perform the necessary due diligence could enjoy an opportunity of historical proportions.

Further robotic Foolishness:

iRobot is a Motley Fool Rule Breakers recommendation, while Microsoft is an Inside Value selection.

Fool contributor Jack Uldrich's favorite John Candy movie remains Stripes, although he still enjoys Planes, Trains, and Automobiles. Jack also owns stock in iRobot. The Fool has a strict disclosure policy.